The present invention relates generally to communication systems. More particularly, and not by way of limitation, the invention is directed to a system and method for correlating different communication sessions.
Correlation is a mathematical term for a statistical measurement on the degree of dependency of two variables. In mathematics, a correlation coefficient is used to indicate the strength and direction of a linear relationship between two random variables. In communication systems, it is desirable to know whether two or more sessions used to set up media streams are correlated in some sense (for example, in the sense that they are used in the same context). Such sessions may be set up and operated under the Session Initiation Protocol (SIP) or other suitable communication protocol. On the terminal side, such a correlation could mean, for example, displaying text from a chat session and video from another session in the same terminal window. On the network side, it could mean, for example, applying some special charging scheme to a multi-service session comprised of two or more individual sessions.
In order to provide these and similar services, it must be determined and communicated how sessions relate to each other. However, there is no inherent mechanism in today's networks that provides the capability to indicate correlation between SIP sessions. Rather, higher level applications utilizing multiple SIP sessions must correlate the sessions at the application level using information available to each particular application. Due to the lack of inherent correlation mechanisms, however, the application level correlations may lead to false correlation assumptions.
What is needed in the art is a system and method for correlating different communication sessions which overcomes the shortcomings of the prior art. The present invention provides such a system and method.